Maxim,
On 9/13/2020 7:42 PM, Maxim Levitsky wrote:
Commit e52d58d54a32 ("iommu/amd: Use cmpxchg_double() when updating 128-bit
IRTE")
accidentally removed an assumption that modify_irte_ga always set the valid bit
and amd_iommu_activate_guest_mode relied on that.
Side effect of this is that on my machine, VFIO based VMs with AVIC enabled
would eventually crash and show IOMMU errors like that:
AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0055 address=0xfffffffdf8000000
flags=0x0008]
Fixes: e52d58d54a321 ("iommu/amd: Use cmpxchg_double() when updating 128-bit
IRTE")
Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
---
drivers/iommu/amd/iommu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 07ae8b93887e5..aff4cc1869356 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3853,6 +3853,7 @@ int amd_iommu_activate_guest_mode(void *data)
entry->hi.fields.ga_root_ptr = ir_data->ga_root_ptr;
entry->hi.fields.vector = ir_data->ga_vector;
entry->lo.fields_vapic.ga_tag = ir_data->ga_tag;
+ entry->lo.fields_remap.valid = 1;
return modify_irte_ga(ir_data->irq_2_irte.devid,
ir_data->irq_2_irte.index, entry, ir_data);
Could you please try with the following patch instead?
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3840,14 +3840,18 @@ int amd_iommu_activate_guest_mode(void *data)
{
struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
+ u64 valid;
if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
!entry || entry->lo.fields_vapic.guest_mode)
return 0;
+ valid = entry->lo.fields_vapic.valid;
+
entry->lo.val = 0;
entry->hi.val = 0;
+ entry->lo.fields_vapic.valid = valid;
entry->lo.fields_vapic.guest_mode = 1;
entry->lo.fields_vapic.ga_log_intr = 1;
entry->hi.fields.ga_root_ptr = ir_data->ga_root_ptr;
@@ -3864,12 +3868,14 @@ int amd_iommu_deactivate_guest_mode(void *data)
struct amd_ir_data *ir_data = (struct amd_ir_data *)data;
struct irte_ga *entry = (struct irte_ga *) ir_data->entry;
struct irq_cfg *cfg = ir_data->cfg;
- u64 valid = entry->lo.fields_remap.valid;
+ u64 valid;
if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) ||
!entry || !entry->lo.fields_vapic.guest_mode)
return 0;
+ valid = entry->lo.fields_remap.valid;
+
entry->lo.val = 0;
entry->hi.val = 0;
--
Thanks,
Suravee
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